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United States Patent |
5,350,368
|
Shields
|
September 27, 1994
|
Tethered butterfly needle trap
Abstract
A a device for preventing inadvertent needle stick injuries from
hollow-bore steel needles on the leading ends of winged or "butterfly"
infusion assemblies. The device comprises a puncture-resistant
semi-flexible conical tube which slides over tubing trailing from the
butterfly needle hub to safely entrap the needle by means of the wings
when the user holds a leading tether firmly over a vein with one hand, and
pulls back on the tailing tubing with the other, such that the wings slide
backward through paired slits until trapped within slots in said cone
whose leading end forms a tether on the superior surface and a horizontal
V-shaped aperture on the inferior surface leading to the paired slits and
slots. The trailing end of said cone is adjusted to releasably grasp the
trailing tubing, or the trailing paraphernalia to which the tubing is
attached, such that the device remains out of the way during insertion and
intended usage of the leading hollow-bore steel needle.
Inventors:
|
Shields; Jack W. (1950 Las Tunas Rd., Santa Barbara, CA 93103)
|
Appl. No.:
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993236 |
Filed:
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December 17, 1992 |
Current U.S. Class: |
604/263; 604/177; 604/198 |
Intern'l Class: |
A61M 005/00 |
Field of Search: |
604/192,198,263,177
128/919
|
References Cited
U.S. Patent Documents
4927415 | May., 1990 | Brodsky | 604/164.
|
4935011 | Jun., 1990 | Hogan | 604/177.
|
4941881 | Jul., 1990 | Masters et al. | 604/162.
|
5030212 | Jul., 1991 | Rose | 604/263.
|
5061250 | Oct., 1991 | Shields | 604/198.
|
5069341 | Dec., 1991 | Barbieri et al. | 206/365.
|
5112311 | May., 1992 | Utterberg et al. | 604/177.
|
5120320 | Jun., 1992 | Fayngold | 604/177.
|
5137515 | Aug., 1992 | Hogan | 604/110.
|
5192275 | Mar., 1993 | Burns | 604/263.
|
5197956 | Mar., 1993 | Brizulla | 604/171.
|
5219339 | Jun., 1993 | Saito | 604/198.
|
Foreign Patent Documents |
425448 | May., 1991 | EP | 604/110.
|
Primary Examiner: Rosenbaum; C. Fred
Assistant Examiner: Alexander; V.
Claims
Therefore, I claim:
1. A tethered trap for safely shielding a hollow-bore steel needle having a
winged hub assembly and trailing cylindrical tubing attached thereto; said
tethered trap comprising a puncture-resistant, semi-rigid hollow cone;
said tethered trap being internally dimensioned to slide over said
trailing cylindrical tubing, and wherein said tethered trap further
comprises:
(a) an open leading end resembling an open mouth with an internal diameter
larger than the external diameter of the hub of said winged hub assembly,
V-shaped recesses on each side, and a superior leading surface extending
to form a flexible tether;
(b) an open trailing end with an internal diameter less than the internal
diameter of said open leading end, and nearly equal to or greater than the
external diameter of said trailing cylindrical tubing,
(c) a body portion between said leading and said trailing end, said body
portion having symmetrically paired horizontal slits extending from said
V-shaped recesses to terminate in paired horizontal slots, the combined
length of said slits and slots being greater than the distance between the
leading tip of said hollow-bore steel needle and the trailing edges of the
wings in said winged hub assembly, the width of said slots being greater
than the thickness of each wing in said winged hub assembly, and the
length of said slots being greater than the distance between the leading
and said trailing edges of said wings where enclosed in said paired
horizontal slots.
2. Said tethered trap, as in claim 1, further comprising said
puncture-resistant, semi-rigid hollow cone with a material thickness
substantially greater in the trailing end of said body portion.
3. Said tethered trap, as in claim 1, further comprising said trailing open
end with an internal diameter greater than the external diameter of paired
flanges on a standard hub permanently attached to the trailing end of said
trailing cylindrical tubing attached to said winged hub assembly.
4. Said tethered trap, as in claim 1 further comprising said trailing open
end with internal diameter or configuration suited to temporarily grasp
the leading conical end of said standard hub attached to said trailing end
of said trailing cylindrical tubing.
5. Said tethered trap, as in claim 1, further comprising said trailing open
end with configuration compatible with temporary immobilization of said
tethered trap by paraphernalia appended to said trailing cylindrical
tubing or to cylindrical tubing trailing said standard hub attached to
said trailing cylindrical tubing attached to said winged hub assembly.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the prevention of accidental hollow-bore
needle-stick injuries in health care workers using winged infusion
assemblies for administering fluid medications in veins or withdrawing
blood.
2. Description of Prior Art
To prevent needle-stick injuries to health care workers, needle guards
which slide over syringes to extend beyond the tip of an injection needle
and,then, lock are now common. Guards which slide over the trailing tubing
in infusion assemblies are less well developed than those which slide and
lock over syringes. However, the former are crucial in preventing
transmissible blood-borne infections, because the leading needles are
usually inserted into veins and, therefore, usually bring back blood in
their bores on withdrawal.
The use of tethers as parts of needle guards have been described by
Slaughter (U.S. Pat. No. 4,781,697 Nov. 1, 1988), Dombrowski et al (U.S.
Pat. No. 4,790,828 Dec. 13, 1988), Corey (U.S. Pat. No. 4,955,866 Sep. 11,
1990), and Simon (U.S. Pat. No. 5,051,109 Sep. 24, 1991). None of these
describe a tether which uses the patient as an anchor.
In U.S. Pat. No. 5,061,250 Oct. 29, 1991, Shields described a tether with a
tab finger-held over a vein aligned pull a slit elastomeric tube
containing a puncture-resistant sheath over a needle during withdrawal.
This system was complex and awkward to owing to orientation of the slit
which captures the needle, the elastomeric nature of the system, and lack
of provision for keeping the tether out of the way when not in use. The
previous invention is not applicable to the instant invention, because the
latter does not incorporate a slit elastomeric tube.
In U.S. patent application 07/956/790 filed Oct. 5, 1992, Shields described
a tethered cylindrical or conical tube with a leading end designed to
safely entrap the hub and leading end of a hollow-bore steel needle whose
trailing end is attached to proximal tubing. The instant invention differs
from the former in that a conical tube with a leading tether embodies a
V-shaped opening beneath the tether; paired longitudinal slits terminating
in slots designed to trap the wings of a butterfly infusion assembly
within the body of said cone, such that the leading hollow-bore steel
needle can be safely trapped; and a variably sized trailing aperture in
the trailing end of said cone, such that the device can be releasably
stabilized, either with respect to the tubing over which said cone slides
or to the paraphernalia on the trailing end of said tubing.
Owing to the alarming rate of increase in HIV, HBV and HCV infections in
health care workers caused by accidental hollow-bore needle sticks after
withdrawal of the needles from the veins of infected patients, urgent
needs now exist for safer equipment, especially paraphernalia used for
giving intravenous infusions or withdrawing blood.
SUMMARY
The object of this invention is to provide and teach novel methods whereby
health care workers can withdraw sharp hollow-bore steel needles from the
veins of patients without exposing the points.
Another object is to provide systems for withdrawing blood or giving
infusions which can be handled like counterparts commonly used, without
encumbrance from apparata intended to prevent accidental needle sticks.
A third object is to provide systems which are simple, reliable, efficient
and easy to use with both hands kept in customary, as well as safe
positions during and after needle withdrawal.
A fourth object is to protect by-standers and health care personnel
responsible for the disposal of tubing with needles still attached.
A final object is to provide a needle safety system which can be
manufactured easily and put to critical care use almost immediately,
especially on phlebotomy and intravenous infusion equipment whose leading
ends are fitted with winged or "butterfly" hubs. (See Drawings).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a diagrammatic axial section of a conical butterfly needle trap
showing the infusion tubing passing through. (Scale 1": 1" in all
drawings).
FIG. 1B is an axial section showing the trailing end of the conical trap
releasably attached to the leading end of the hub on the wailing end of
the tubing.
FIG. 2 is a diagrammatic axial section of the conical butterfly needle trap
shown in FIG. 1A, but without enclosed infusion tubing and rotated
90.degree. to the left.
FIG. 3 is a an axial section of the conical butterfly needle trap like that
in FIG. 1A showing the butterfly needle wings partially pulled into paired
slits by traction on the trailing tubing.
FIG. 4 is an axial section like that in FIG. 2, showing the butterfly
needle wings trapped within paired slots in the body of the conical trap.
FIG. 5A is an axial section like that in FIG. 1, showing a trailing
aperture in the cone large enough to allow passage of a standard needle
hub therethrough.
FIG. 5B is an axial section like that in FIG. 1, showing an aligned
luer-slip hub.
FIG. 5C is a diagrammatic illustration of a supplementary useful clamp.
FIG. 5D is an axial section like that in FIG. 1, showing an aligned
Luer-Lok hub.
FIG. 6 is an axial section like that in FIG. 2, showing the cone bisected.
FIG. 7 depicts a hinging clamp for reconstituting the bisected cone.
FIG. 8 shows the reconstituted cone enclosing infusion tubing.
DESCRIPTION OF PREFERRED EMBODIMENTS
A first preferred embodiment of this tethered butterfly needle trap is
shown in FIGS. 1-4. As shown in FIG. 1A, the trap consists of a conical
semi-rigid puncture-resistant tube, hereinafter called a cone (11), which
slides over flexible intravenous infusion tubing, hereinafter referred to
as tubing (12). The leading end of the cone is cut away underneath and
diagonally at point (13) to leave a flexible tether (14) whose superior
leading surface (15) is made rough to increase friction when grasped or
held down by a finger. The trailing end of the cone (16) narrows sharply
to leave a trailing aperture (17) whose diameter is slightly smaller than
the external diameter of the tubing (12).
As shown in FIG. 1B, the trailing end of the tubing (12) is permanently
attached to the leading end of a hub (18). In winged infusion assemblies
wherein the tubing is of small diameter, the trailing aperture (17) in the
trailing end of the cone (16) is optionally made larger, such that it
releasably grasps the leading conical part of the needle hub (19), instead
of the tubing.
As shown at a 90.degree. angle in FIG. 2, the leading cut-away portion of
the cone (11) leaves a flexible tether (14) whose leading end (15) swings
over the leading mouth (21 ) of the cone when downward pressure is applied
in the direction of the arrow at (22). An additional diagonal cut (23)
into the leading end of the cone leaves a horizontal V-shaped aperture
leading to symmetrically paired longitudinal slits (24) which terminate in
symmetrically paired slots (25) capable of symmetrically conveying and,
then, trapping the paired wings of a butterfly needle.
As shown in FIG. 3, when the cone (11) is slid forward over the tubing (12)
in the direction of the arrow at (31), the leading tether (14-15) will
come to rest over the skin-submerged hollow-bore steel needle (32); while
the exposed hub (33) and wings (34) of the butterfly needle will come to
rest in the open V-shaped mouth (21) of the cone shown in FIG. 2.
As shown at a 90.degree. angle in FIG. 4, when a finger of one hand presses
downward in the direction of the arrow at (41) to prevent venous bleeding,
as well as stabilize the tether; while the other hand pulls back the
trailing tubing in the direction of the arrow at (42), the resultant
forces will retract the paired butterfly wings (34) through the paired
slits (24) until the wings become trapped in the paired slots (25). Then,
the hollow-bore steel needle (32-dotted lines) will be effectively
enclosed within the confines of the cone (11), such that its sharp tip or
shaft will not be exposed after use tier the intended purposes of
conveying infusions or withdrawing blood.
It should be added that making the cone thinner at its leading end and
thicker at its trailing end, as depicted by line thickness at (43) in FIG.
4 and included in FIGS. 5-6 will lend more flexibility at the leading end
for the tether (14), lower part of the V-shaped opening (23) and the slit
(24); while lending more stability to the slot (25) and closure of the
slit (24) after the wings (34) have passed through into the slot (25).
To operate this tethered butterfly needle trap, the user manipulates the
leading winged infusion needle just like he/she would do under customary
circumstances by hooking up the trailing hub (18) to connectors emanating
from an infusion bag or bottle; flushing air from the assembly; removing
the customarily supplied scabbard from the hollow-bore steel infusion
needle; inserting the needle into a well-chosen vein; and giving the
infusion or series of infusions. However, when it's time to withdraw the
needle from the vein of a patient, the user will grasp the leading tether
(14,15); pull the cone (11) forward until the lower V-shaped portion (23)
slides under the hub (33) of the butterfly; place a sterile pledget over
the venepuncture site; press down on the roughened leading end of the
tether (15); and, then, pull back on the trailing tubing (12) until the
hollow-bore steel needle is trapped within the slot (25) in the cone (11)
by means of its paired wings (34). In addition, to "fail-safe", it is wise
to slide the originally supplied scabbard back over the hollow-bore steel
needle (32) in the event that the needle is inclined to wobble enough to
exit the slit, or the event that co-workers are careless during disposal
of this tethered butterfly needle trap.
In a second preferred embodiment, as shown in FIG. 5A, the trailing
aperture (17) in the cone (11) is made larger in internal diameter than
the external diameter of the trailing flanged end (51) of the hub (18)
permanently attached to the trailing end of the tubing (12), e.g. >7.5
mm.; as well as greater than that of the largest external diameter of the
fitting luer-slip connector (52), shown below in FIG. 5B. As results, the
cone (11) will slide proximally over the luer-slip connector (52) in the
direction of the arrow (53) until an object of even larger external
dimension is encountered along the proximal course of the tubing (54).
Supplemental provision of an open-ended clamp (55), shown in FIG. 5C,
designed to clasp over the luer-slip connector (52) in the direction of
the arrow (56) will prevent forward sliding of the retracted cone and keep
said cone even more remote from the winged infusion needle before and
during the intended use without interfering with flow through the
essential tubing. After the winged infusion needle is used for its
intended purposes, the clamp (55) can be removed to allow free sliding of
the cone (11) forward over distal tubing (12) until the cone and its
leading parts shown in FIGS. 1-4 become useful for enclosing the
hollow-bore steel needle (32).
In a third preferred embodiment, as shown by the dotted lines (57) in FIG.
5A, the cone can be made cylindrical, such that it will allow passage
therethrough of an aligned Luer-Lok hub (58), as shown in FIG. 5D. Again,
an open ended clamp (55) applied in the direction of the arrow (56) will
prevent the cylinder (57) from sliding over the Luer-Lok hub (58) until
the leading parts of the cone (11) are needed for enclosing the
hollow-bore steel needle.
In a fourth preferred embodiment (not illustrated), the cone can be made
ovoid, instead of round, especially at the leading end. This modification
in the shape of the opening shown at (21) beneath the tether (14,15) in
FIG. 2 will decrease the angle at which the paired wings (34) on the
butterfly needle hub (33) enter the paired slits (24) in the cone (11 )
when the trailing tubing (12) is manually retracted.
In a fifth, but not necessarily preferred embodiment, the cone can be
laser-slit to the trailing end or molded in two matching parts securely
apposed by means of a clasping mechanism, as shown diagrammatically in
FIGS. 6-8. This modification will allow application of the conical needle
trap to "butterfly" infusion needles already assembled by various
manufacturers. For instances: as shown in FIG. 6, the cone (11) can be
slit into or molded in two parts (61 and 62), each supplied with a flange
(63) on the outside of the trailing end. As shown in FIG. 7, a rigid clasp
(71) with a central hinge (72) and mutually embracing arms (73,74) can
hold the two half-cones together. As shown in FIG. 8, when the rigid
conical clasp (71) is secured to reconstitute the full cone (11), forward
movement will be stopped by the diameter of the cone; while backward
slipping will be stopped by the flange (63). Thus constituted to surround
the trailing infusion tubing on a winged needle hub depicted by leading
(81) and trailing (82) dotted lines, the reconstituted cone will serve as
shown previously in FIGS. 1-4, and as outlined verbally in the first
preferred embodiment.
While it would seem that polypropylene or tygon would be optimal materials
from which to mold such cones currently, it will be appreciated by those
skilled in the art that variations in materials, dimensions and details
can be made without departing from the spirit of this invention. Finally,
it should be mentioned that these specifications supplement those set
forth in U.S. patent application No. 07/956,790 filed Oct. 5, 1992 with
respect to tether attachment, texture, opening forms, body configuration
and trailing end modifications.
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